Numerous lift and transfer devices have been developed to assist handicapped persons with respect to movement between various positions such as between a wheelchair and a bed, or to a bath tub, or to assist the person in standing. While many of the known devices have performed in a satisfactory manner for some functions, nevertheless most such devices are limited with respect to the satisfactory performance of only one or a small number of functions, and are incapable of effectively permitting transfer or manipulation of the person over a wide range of functions.
Another problem experienced with many of the known lifts is the manner of support for the handicapped persons. Many conventional lifts utilize a harness or swing arrangement which is supported solely in a suspended manner from an overhead arm or beam, and this results in undesired freedom in that the harness readily swings and can be frightening to the person during transfer or during movement of the lift device.
Still another problem experienced with many of the known lifts is their inability to be powered driven and controlled by the person supported by the lift. That is, the known lifts having a wheeled chassis, and specifically lifts having side legs which are movable transversely between inner and outer positions, have typically required that the rolling movement of the lift be effected due to pushing thereof by a helper. Further, in those situations where a power assist is provided for moving the lift arm, the controlling of the movement of the lift arm has also typically been possible only by a helper, and not by the person supported from the lift arm.
Many of the known lift devices are also disadvantageous in that the supporting frame is often defined by a pair of widely spaced legs which, due to the overall width, prevents the device from being readily moved through conventional doorways. To improve on this, some known lifts have provided legs which can be swingably moved between inner positions which permit movement through doorways, and outer diverging positions which accommodate furniture therebetween, such as a wheelchair. With these latter known lifts, however, the swinging movement of the legs between the inner and outer positions is normally accomplished by a mechanism which is mechanical and involves some type of swinging lever mounted on the front frame of the lift, which front frame often comprises an upright central beam or post. This swinging lever generally cannot be operated by the handicapped person, but must be operated by a helper.
Some examples of known lifts are disclosed by U.S. Pat. Nos. 3,940,808, 4,545,085, 4,554,691, 4,569,094, 4,918,771, 5,117,516, 5,388,289, 5,412,820, 5,459,891, 5,502,851, and 5,560,054.
It is an object of this invention to provide an improved lift and transfer device for a handicapped person, which improved device is believed to provide improved functional capabilities and performance and is believed to overcome many of the disadvantages associated with prior such devices.